Unable to connect to cluster

Problem

User cannot connect to the Okera cluster

Solution

The Okera UI is accessed through the REST server endpoint. It may be unresponsive for a few reasons: The endpoint is incorrect, the cluster is unhealthy, the planner is unavailable, or the REST service has an issue.

curl <url>:<port>

The curl command should return “Empty response from server” or something similar. If the endpoint is not responsive, check the cluster.

kubectl [-n <namespace>] get pods -o wide

If the cluster is not healthy, or there have been multiple consecutive restarts, further investigation is required to determine whether the issue is at the pod or node level. 

Otherwise, if all the pods appear healthy( State=Running and Ready Status=(1/1) ), check the service.

kubectl [-n <namespace>] get svc
kubectl [-n <namespace>] describe service cdas-rest-server

• Are the ports assigned?
• Do they match the endpoint the user is accessing?
• If there are multiple REST servers, check whether any of the endpoints are responding.

curl -k https://REST_endpoint_1:port

curl -k https://REST_endpoint_2:port 

If the services are up, curl should respond with "HTTP ERROR 401 Unauthorized". Otherwise, 

kubectl [-n <namespace>] logs <rest server pod>

kubectl [-n <namespace>] get deployment -owide cdas-rest-server

kubectl [-n <namespace>] describe deployment cdas-rest-server

Check the Load Balancer

• Are all the REST server pods registered?
• Are there enough ELBs?
• Are there sufficient IP addresses?

Last Resort

Delete and allow Kubernetes to recreate the pod.

kubectl [-n <namespace>] delete pod <cdas-rest-server pod>